Silicon photonic devices can be made using existing semiconductor fabrication techniques, and because silicon is already used as the substrate for most integrated circuits, it is possible to create hybrid devices in which the optical and electronic components are integrated onto a single microchip. Consequently, silicon photonics is being actively researched by many electronics manufacturers, as well as by academic research groups, who see it is a means for keeping on track with Moore's Law, by using optical interconnects to provide faster data transfer both between and within microchips.
An optical ring resonator is a set of waveguides in which at least one is a closed loop (e.g., the ring) coupled with some sort of light input and output. (These can be, but are not limited to, waveguides.) When light of the resonant wavelength is passed through the loop from input waveguide, it builds up in intensity over multiple round-trips due to constructive interference and is output to the output bus waveguide which serves as a detector waveguide. Because only a select few wavelengths will be at resonance within the loop, the optical ring resonator may function as a filter. A silicon ring resonator is an optical ring resonator using silicon as both the ring and the waveguide(s).